Transcript science - Fullfrontalanatomy.com

Chapter 1
Introduction: Biology Today
PowerPoint® Lectures for
Campbell Essential Biology, Fourth Edition
– Eric Simon, Jane Reece, and Jean Dickey
Campbell Essential Biology with Physiology, Third Edition
– Eric Simon, Jane Reece, and Jean Dickey
Lectures by Chris C. Romero, updated by Edward J. Zalisko
© 2010 Pearson Education, Inc.
What to know about this chapter:
1. What is science?
2. How do scientists gather knowledge?
3. What is the scientific method?
4. What is the scope of life?
5. What are the levels of life?
6. How does energy flow through an ecosystem?
7. What is DNA?
8. What is diversity?
© 2010 Pearson Education, Inc.
Biology and Society:
Biology All Around Us
• We are living in a golden age of biology.
• Biology provides exciting breakthroughs changing our culture.
– Molecular biology is solving crimes and revealing ancestries.
– Ecology helps us address environmental issues.
– Neuroscience and evolutionary biology are reshaping psychology and
sociology.
– How many subdivisions of Biology can you think of?
© 2010 Pearson Education, Inc.
Figure 1.00
THE SCOPE OF LIFE
The Properties of Life
• Biology is the scientific study of life.
– Life is structured on a size scale ranging from the molecular to
the global.
– Biology’s scope stretches across the enormous diversity of life on
Earth.
– Life had to have been given a “scientific” description, so the
following characteristics encompass that description.
© 2010 Pearson Education, Inc.
a Order
Figure 1.1ba
b Regulation
Figure 1.1bb
c Growth and development
Figure 1.1bc
d Energy utilization
Figure 1.1bd
e Response to the environment
Figure 1.1be
f Reproduction
Figure 1.1bf
g Evolution
Figure 1.1bg
Life at Its Many Levels
• Biologists explore life at levels ranging from the biosphere to the
molecules that make up cells.
© 2010 Pearson Education, Inc.
Biosphere
Ecosystems
Communities
Populations
Figure 1.2-1
Biosphere
Ecosystems
Communities
Populations
Organisms
Organ Systems
and Organs
Tissues
Figure 1.2-2
Biosphere
Ecosystems
Communities
Populations
Organisms
Organ Systems
and Organs
Organelles
Tissues
Molecules and Atoms
Atom
Nucleus
Cells
Figure 1.2-3
Biosphere
Figure 1.2a
Ecosystems
• Each organism interacts continuously with its environment.
– Organisms interact continuously with the living and nonliving
factors in the environment.
– The interactions between organisms and their environment take
place within an ecosystem.
• The dynamics of any ecosystem depend on two main processes:
– Cycling of nutrients
– Flow of energy
© 2010 Pearson Education, Inc.
Loss of
heat
energy
ECOSYSTEM
Inflow
of light
energy
Consumers
animals
Chemical
energy
food
Producers
plants and other
photosynthetic
organisms
Cycling
of
nutrients
Decomposers
in soil
Figure 1.3
Cells and Their DNA
• The cell is the lowest level of structure that can perform all
activities required for life.
– All organisms are composed of cells.
© 2010 Pearson Education, Inc.
• Genetic engineering and biotechnology have allowed us to
manipulate the DNA and genes of organisms.
• Bacteria can make insulin because a gene for insulin production
was transplanted into their DNA.
• All of life is possible because of DNA. That is all that is needed
to “spawn” life
• The ability of a cell to reproduce has given all living things that
ability to continue as long as there is utilizable energy to keep
thier cellular mechanisms running.
© 2010 Pearson Education, Inc.
This is where the
“magic” happens
The four
chemical
building blocks
of DNA
A DNA molecule
Figure 1.5
Life in Its Diverse Forms
• Diversity is the hallmark of life.
– The diversity of known life includes 1.8 million species.
– Estimates of the total diversity range from 10 million to over 100
million species.
• Biodiversity can be beautiful but overwhelming.
• Taxonomy is the branch of biology that names and classifies
species.
– It formalizes the hierarchical ordering of organisms.
© 2010 Pearson Education, Inc.
Figure 1.7
The Three Domains of Life
“Scientists” have placed all living things in a huge library
according to different criteria. This is called systematics or
taxonomy. The highest level is called a Domain
• The three domains of life are
– Bacteria
– Archaea
– Eukarya
© 2010 Pearson Education, Inc.
DOMAIN EUKARYA
Colorized TEM
DOMAIN
BACTERIA
Kingdom Plantae
Kingdom Fungi
LM
TEM
DOMAIN
ARCHAEA
Kingdom Animalia
Protists (multiple kingdoms)
Figure 1.8
THE PROCESS OF SCIENCE
• The word science is derived from a Latin verb meaning “to
know.”
– Science is a way of knowing.
– Science developed from people’s curiosity about themselves and
the world around them.
• Science seeks natural causes for natural phenomena.
– This limits the scope of science to the study of structures and processes
that we can observe and measure.
• Verifiable observations and measurements are the data of
discovery science.
– In biology, discovery science enables us to describe life at its many
levels.
© 2010 Pearson Education, Inc.
Figure 1.14a
• Discovery science can lead to important conclusions based on a
type of logic called inductive reasoning.
– An inductive conclusion is a generalization that summarizes many
concurrent observations.
© 2010 Pearson Education, Inc.
Hypothesis-Driven Science
• As a formal process of inquiry, the scientific method consists of
a series of steps.
– The key element of the scientific method is hypothesis-driven
science.
– http://youtu.be/bNc9vWLDSCA
– Be sure to do the Scientific Method exercise here:
http://www.gc.maricopa.edu/biology/glacier/scientific_method/
– Just hit continue! Don’t enter username and passwords on the first two
pages
© 2010 Pearson Education, Inc.
Revise
Observation:
My flashlight
doesn’t work.
Question:
What’s wrong
with my
flashlight?
Hypothesis:
The flashlight’s
batteries
are dead.
Experiment does
not support
hypothesis; revise
hypothesis or
pose new one.
Prediction:
If I replace the
batteries, the
flashlight will
work.
Experiment:
I replace the
batteries with
new ones.
Experiment
supports
hypothesis;
make additional
predictions
and test them.
Figure 1.15-3
• Dietary fat comes in different forms.
• Trans fat is a non-natural form produced through manufacturing
processes.
• Trans fat
– Adds texture
– Increases shelf life
– Is inexpensive to prepare
© 2010 Pearson Education, Inc.
• A study of 120,000 female nurses found that high levels of trans
fat nearly doubled the risk of heart disease.
© 2010 Pearson Education, Inc.
• A hypothesis-driven study published in 2004
– Started with the observation that human body fat retains traces of
consumed dietary fat.
– Asked the question: Would the adipose tissue of heart attack
patients be different from a similar group of healthy patients?
– Formed the hypothesis that healthy patients’ body fat would
contain less trans fat that the body fat in heart attack victims.
© 2010 Pearson Education, Inc.
• The researchers set up an experiment to determine the amounts
of fat in the adipose tissue of 79 patients who had a heart attack.
• They compared these patients to the data for 167 patients who had
not had a heart attack.
• This is an example of a controlled experiment, in which the
control and experimental groups differ only in one variable—the
occurrence of a heart attack.
© 2010 Pearson Education, Inc.
• The results showed significantly higher levels of trans fat in the
bodies of the heart attack patients.
© 2010 Pearson Education, Inc.
Trans fats in adipose tissue
g trans fat per 100 g total fat
2.0
1.77
1.48
1.5
1.0
0.5
0
Heart attack
patients
Control
group
Figure 1.16
Theories in Science
• What is a scientific theory, and how is it different from a
hypothesis?
– A theory is much broader in scope than a hypothesis.
– Theories only become widely accepted in science if they are
supported by an accumulation of extensive and varied evidence.
© 2010 Pearson Education, Inc.
• Scientific theories are not the only way of “knowing nature.”
• Science and religion are two very different ways of trying to make
sense of nature.
© 2010 Pearson Education, Inc.
The Culture of Science
• Scientists build on what has been learned from earlier research.
– They pay close attention to contemporary scientists working on the
same problem.
• Cooperation and competition characterize the scientific culture.
– Scientists check the conclusions of others by attempting to repeat
experiments.
© 2010 Pearson Education, Inc.
Figure 1.17
Science, Technology, and Society
• Science and technology are interdependent.
– New technologies advance science.
– Scientific discoveries lead to new technologies.
– For example, the discovery of the structure of DNA about 50 years
ago led to a variety of DNA technologies.
© 2010 Pearson Education, Inc.
– Technology has improved our standard of living in many ways, but
it is a double-edged sword.
– Technology that keeps people healthier has enabled the human
population to double to nearly 7 billion in just the past 40 years.
– The environmental consequences of this population growth may be
devastating.
© 2010 Pearson Education, Inc.
Figure 1.18
Evolution Connection:
Evolution in Our Everyday Lives
• Antibiotics are drugs that help fight bacterial infections.
• When an antibiotic is taken, most bacteria are typically killed.
• Those bacteria most naturally resistant to the drug can still
survive.
• Those few resistant bacteria can soon multiply and become the
norm and not the exception.
© 2010 Pearson Education, Inc.
• The evolution of antibiotic-resistant bacteria is a huge problem in
public health.
• Antibiotics are being used more selectively.
• Many farmers are reducing the use of antibiotics in animal feed.
© 2010 Pearson Education, Inc.
Figure 1.19
Colorized SEM